diff --git a/plugin/plugin.go b/plugin/plugin.go
new file mode 100644
index 000000000000..ee6ad608d8b6
--- /dev/null
+++ b/plugin/plugin.go
@@ -0,0 +1,19 @@
+package plugin
+
+import "github.com/gogo/protobuf/proto"
+
+type Host interface {
+	// Expect tells the host to expect that every registered protobuf type which
+	// implements the protobuf interface name (cosmos_proto.implements_interface)
+	// is expected to register a golang interface implementation of type golangInterfaceType.
+	Expect(protoInterfaceName string, golangInterfaceType interface{})
+
+	// Register registers plugin handler constructors which are functions taking a plugin target
+	// and returning a handler type. Ex: func(secp256k1.PubKey) crypto.PubKey.
+	Register(handlerConstructors ...interface{})
+
+	// Resolve resolves the handler for the provided target. Ex:
+	//  var pubKey crypto.PubKey
+	//  host.Resolve(&secp256k1.PubKey{}, &pubKey)
+	Resolve(target proto.Message, handler interface{}) error
+}
diff --git a/plugin/plugin_test.go b/plugin/plugin_test.go
new file mode 100644
index 000000000000..1bc26f64d489
--- /dev/null
+++ b/plugin/plugin_test.go
@@ -0,0 +1,48 @@
+package plugin_test
+
+import (
+	"github.com/gogo/protobuf/proto"
+
+	"github.com/cosmos/cosmos-sdk/crypto/keys/ed25519"
+	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
+	"github.com/cosmos/cosmos-sdk/crypto/types"
+	"github.com/cosmos/cosmos-sdk/plugin"
+)
+
+type PubKeyModule struct{}
+
+type AuthModule struct{}
+
+type SecpHandler struct{ *secp256k1.PubKey }
+
+func NewSecpHandler(pubKey *secp256k1.PubKey) types.PubKey { return &SecpHandler{PubKey: pubKey} }
+
+type EdHandler struct{ *ed25519.PubKey }
+
+func NewEdHandler(pubKey *ed25519.PubKey) types.PubKey { return &EdHandler{PubKey: pubKey} }
+
+func (m PubKeyModule) Provide(host plugin.Host) {
+	host.Register(
+		NewSecpHandler,
+		NewEdHandler,
+	)
+}
+
+func (m AuthModule) Provide(host plugin.Host) AuthKeeper {
+	host.Expect("cosmos.crypto.PubKey", (*types.PubKey)(nil))
+	return AuthKeeper{pluginHost: host}
+}
+
+type AuthKeeper struct {
+	pluginHost plugin.Host
+}
+
+func (k AuthKeeper) GetAddress(pubKeyProtoType proto.Message) types.Address {
+	var pubKey types.PubKey
+	err := k.pluginHost.Resolve(pubKeyProtoType, &pubKey)
+	if err != nil {
+		panic(err)
+	}
+
+	return pubKey.Address()
+}